arXiv subjects

Katsuhiko Suzuki

Publications and source records attributed to Katsuhiko Suzuki.

23 records · Page 2Linked to original sources

arXiv1999

Quark recombination model for polarizations in inclusive hyperon productions at high energy

We investigate the transverse polarization of hyperons produced by the photon induced reactions using the quark recombination model. This model reproduces polarizations of hadrons produced by the hadron-hadron collisions and accounts for the origin of the empirical rule by DeGrand and Miettinen. We find significant polarizations in the hyperon photoproduction by applying this model to the $γN \ra \Lam $ $(Σ^{0}) + X$ reaction.

hep-ph↗

arXiv1995

Off-shell pion structure function and flavor asymmetry in the nucleon sea

We study off-shell effects of the pion cloud on the sea quark distribution in the nucleon. The structure function of the off-mass-shell pion is obtained within the Nambu and Jona-Lasinio model, where the shape of the distribution function depends on the pion momentum. By using the momentum dependent pion structure function, the SU(2) flavor asymmetry in the nucleon see is reexamined within the pionic model, in which the sea quark distribution of the nucleon is given as a convolution of the off-shell pion structure function. We calculate experimentally observed quantities related to the SU(2) asymmetry of the nucleon sea such as the Gottfried sum and the Drell-Yan cross section ratios, and find these quantities are insensitive to the off-shell effects of the pions structure function. However, the $x$ dependence of $\bar{u}-\bar{d}$ calculated with the off-shell structure function shows a clear deviation from the result with the on-shell one. We evaluate also the cross section of semi-inclusive lepton-nucleon process with a slow nucleon production to demonstrate the off-shell effect to be checked experimentally.

hep-ph↗

arXiv1995

Pion structure function in nuclear medium

We study the pion structure function in nuclear medium using the Nambu and Jona-Lasinio model, and its implication for the nuclear pion enhancement of the sea quark distribution in nuclei. By using the operator product expansion, medium effect of the nuclear matter is incorporated in calculations of the twist-2 operators. We find density dependence of the pion structure function is rather weak around the nuclear matter density. We also discuss how the medium modification of the pion structure affects the sea quark enhancement in the nucleus.

hep-ph↗

arXiv1994

Heavy Quarkonium in the dual Ginzburg-Landau theory of QCD

We study the masses and the leptonic decay widths of heavy quarkonium in the dual Ginzburg-Landau (DGL) theory of QCD, in which the abelian monopole condensation plays an essential role for color confinement. The effect of color screening due to the light quark pair creation is introduced by the infrared momentum cutoff in the gluon propagator. We find that the color screening effect is important to reproduce the properties of the heavy quarkonium, in particular the leptonic decay width. We also discuss the underlying systematics of the heavy quark spectroscopy in the DGL theory.

hep-ph↗

arXiv1994

Roles of Diquarks in the Nucleon for the Deep Inelastic Scattering and the Non-leptonic Weak Transitions

We study roles of quark-quark correlations in the baryons for the deep inelastic structure function and the $ΔI=1/2$ rule of the non-leptonic weak hyperon decay. The quark-quark correlation is incorporated phenomenologically as diquarks within the Nambu and Jona-Lasinio model. The strong diquark correlations in the spin-0 channel enhance the $ΔI=1/2$ weak matrix elements, and account for the $ΔI=1/2$ rule. The ratio of the nucleon structure functions $F_2^{n}(x)/F_2^{p}(x)$ also comes to agree with experiment due to the diquark correlations.

hep-ph↗